Code
gosu-n3wton
Inspired by the Flash game N3wton, http://www.kongregate.com/games/Zyzic/n3wton this is an attempt to replicate its physics in gosu.
Also see: http://www.slideshare.net/vishnu/simple-game-development-with-ruby/
You propel your character via its bullets and try to shoot enemies off screen.